Mechano-electrical transducer



Jan. 15, 1957 Filed June 10, 1954 J. M. STOLZ MECHANO-ELECTRICAL TRANSDUCER 2 Shee ts-Sheet l .9 .8 .7 6 .54 lHlllllllllllilllllllllll INVENTOR.

JAMES M STOLZ BY amw.

Jan. 15, 1957 s L 2,777,925

MECHANO-ELECTRICAL TRANSDUCER Filed June 10, 1954 2 Sheets-Sheet 2 INVENTOR.

JAMES M. STOLZ F/ [g 5 By United States MECHANO-ELECTRICAL TRANSDUCER James M. Stolz, Los Angeles, Calif.

Application June 10, 1954, Serial No. 435,793

12 Claims. (Cl. 201-62) Generally speaking, the present invention relates to the transducer art and, more particularly, pertains to an improved mechano-electrical transducer adapted to translate mechanical movement (or variations in physical position) into correlated electrical variations (such as electrical resistance variations, for example). For example, one form of the present invention is particularly well adapted for use as a precision mechanico-electrical micrometer suitable for very rapidly and easily making extremely precise spatial measurements (although, not so limited). Also, the present invention may comprise a variable potentiometer, a variable rheostat, or a mechanically operated variable electrical resistor having virtually infinite resolution.

I am aware of the fact that various mechanico-electrical transducers, variable potentiometers, and variable rheostats have been developed heretofore. However, all of such prior art devices, known to me, have serious disadvantages of one type or another.

For example, most such prior art devices have encountered a major problem in attempting to produce a discrete, substantial, measurable change in electrical resistance in response to an extremely small mechanical movementthey have encountered resolution problems. For example, in prior art mechanico-electrical transducers of the type using an electrical resistance element (usually, a Wire made of a metal or an alloy of metals having high electrical resistivity), it has been found virtually impossible to make such an electrical resistance element of a relatively short length having as high an electrical resistance as would be desirable in order to provide efficient mechanico-electrical transducing. Therefore, prior art attempts to solve this problem have been made and have taken the form of the employment of such electrical resistant elements of extremely small cross-sectional area (whereby to maximize resistance per unit length) and have also taken the form of such electrical resistance elements of helically coiled electrical resistance wire (to maximize resistance per unit length along the axis of the coil). Both of these prior art attempts to solve the abovereferred-to problem have serious disadvantages. In the first case, the employment of an electrical resistance wire of extremely small cross-sectional area has been impractical because such wire is extremely difficult and costly to produce and, in addition is so fragile as to render the entire mechanico-electrical transducer so susceptible to shock and vibration, or movement of any kind, as to be virtually inoperative for all practical purposes. Second, the use of a resistance element of helically coiled Wire produces noise and resolution problems of a substantial measure. In this prior art version, it is virtually impossible to maintain small-area contact with a limited portion of an electrical wire forming a part of the helical coil.

Generally speaking, the present invention includes at least a first and second electrical conductor (usually, a plurality of sets thereof) each having electrical resistance which is a function of the length thereof from a first point thereon (usually, an arbitrary and/ or imaginary point) to a second point thereon (usually, an arbitrary and/or imaginary point). The invention may also include electrical contact means cooperably arranged for electrical contact with said first and second electrical conductors whereby to electrically connect said first and second electrical conductors (of each set, independently, when a plurality of sets are employed). The electrical contact means being relatively movably mounted (usually, relatively slidably movably mounted) with respect to said first and second electrical conductors whereby said elec trical contact means may be relatively moved in electrical contact (usually slidably moved) with said first and sec- 0nd electrical conductors between said first points thereon and said second points thereon whereby to effectively vary the electrical resistance from said first point on said first electrical conductor to said first point on said second electrical conductor (or in the event that a plurality of sets are used, to effectively vary the electrical resistance from the first point on the first electrical conductor of the first set to the first point on the second electrical conductor of the last set) as a function of the position of the electrical contact means with respect to said first and second electrical conductors.

In the form of the present invention employing a plurality of sets of electrical conductors, means is also provided for electrically connecting the first point of the second electrical conductor of each set (except the last set) to the first point of the first electrical conductor of a different set (except the first set).

One preferred generic form of the present invention may also include measuring means comprising a first member and a second member relatively movable with respect to each other in correlation with the relative movement of the electrical contact means with respect to the first and second electrical conductors (or with respect to the plurality of sets thereof).

From the above description of basic and preferred generic forms of the present invention, it will be apparent to those skilled in the art that virtually all of the hereinbefore-referred-to prior art disadvantages and/or problems are virtually and entirely eliminated and/or overcome in and through the use of the present invention.

For example, it is obvious that the apparatus of the present invention effectively multiplies the normally small electrical resistance change occurring in a single electrical conductor (of high electrical resistance wire) in response to a very small movement of the electrical contact member therealong, by a factor that equals the number of electrical conductors employed. This makes it possible to produce virtually any desired ratio of resistance change with respect to mechanical movement of the electrical contact means and also makes it possible to cause the entire transducer to have a desired overall electrical resistance. Furthermore, the electrical contact means slidably contacts each wire individually in an extremely small contact areatherefore, the device has an extremely high resolution, which can be increased to any desired degree (and, therefore, may be said to be virtually infinite) by merely increasing the number of electrical conductors employed.

Furthermore, it should be noted that the device of the present invention does not require that the electrical conductors be made of such small cross-sectional area as to be extremely fragile. Actually, they may be of relatively rugged construction, and the necessary sensitivity of the device may be provided by merely increasing the number of electrical conductors.

Furthermore, it is obvious that the form of the present invention provided with measuring means comprises a arr/7,9125

very effective mechano-electri'cal micrometer suitable rc'rprecisienspati a1 measurements With the above points in mind, it is the object of the present invention to provide an improved mechanico-electri aljjtransduc'er 'a'n'd/or" variablepotentiometer and/or vari'ahle rheostat arid/or "mechanically operable, variable electrical resistor "6f -simple, cheap 'andrugg'ed construction and'embodyingvirtually any" desired degree of sensi tivityahd'resolution.

-Itis' afurtherobject of the present invention -to 'pro'viiie animprovedmechanico electrical'micrometer torprecision spa'tiahmeasurement and "of simple, cheap and rugged construction and embodying virtually 'any desired degree ofs'en'sit ivity'turd-resolution.

@ther andalli'edobiects will be apparentto those-skilled in *the art' after a care ful perusal, examination a'rrdstu'dy of thenc'companying illustrations, the present specification,' andjthe appended-claims.

'To facilitate understanding, "reference i will be made to the h'e'reinbelow described "drawings, in which:

Fig; 1 is a perspective view of one illustrative embodiment of'the'presentinvention;

Fig. 2 is a front elevationof 'balancing apparatus and indicating means cooperable with' the apparatus illustr ated in Fig. l 'to form amechanico-electric al micrometer or 'sp'atia'l-measuring apparatus;

Fig. 3 is an electrical schematic view illustrating the cooperative relationship of the-apparatus shown in Fig. 1 and the apparatus shown in Fig. 2 (plus-a power'su'pply) to comprise -a complete mechanico-electrical micrometer orspati'almeasuring apparatus;

Fig. 4-is a longitudinal, vertical 'sectional' view of -a slightly'modified form of mechanico-electrical transducer equivalent 'to that shown in Fig. l but constructed differently therefrom;

Fig. Sis a vertical sectional view taken inthedirection of the arrows V-V in Fig. 4 (and somewhat enlarged with-respect to Pig. 4);

Fig. 6 is'a fragmentary,diagrammatic, schematic view indicating the operation of the form of the invention shown in Figs. 4 and 5 (although the physical structure has been somewhat simplified in Fig. 6 for reasons of clarity);

Fig. 7 is a fragmentary view similar to Fig. 6 but'on a somewhat larger scale; I

Fig, 8 is a view similar to a portion of Fig. 3 and illustrates a slight modification of the circuit connecting the meter with respect to the Wheatstone bridge; and

Fig. 9 is a fragmentary plan view of a small portion of the scale carried on the upper surface of the device shown in 'Fig. 1.

Generally speaking, the device of the present invention includes atleast one set of electrical conductors comprising a first electrical conductor having electrical resistance which is a "function of the length 'thereoffrom the first pointther'eon to a second point thereon, and a second electrical c'onductorhaving electrical resistance which is afunction of the length thereof from a first pointthere'on to a seco'ndfpoint thereon. In the specific example illustrated in Fig. 3, this takes theforrn of four sets of electrical conductors A, B,'C, and D, including, respectively, a first electrical conductor 'iA and a second electrical conductor 2A, a first electrical conductor 18 and a se'condele'ctrical conductor 28, a first electrical conductor 1C and a'second electrical 'con'ductorZC, a first electrical conductor 1D and a second electrical conductor 21). In the specific example illustrated, the first point (mentioned above) on each electrical conductor is indicated at F and the'second'p'oint on each electrical conductor is indicated at S.

Also, generally speaking, in the form of the present invention employing morethan one set of electrical conductors (such as the form illustratedin Figs. 1 and 3 employing four sets of-electrical conductors) means may alsobep'rovide'd to electrically connect the'first point of the second electrical conductor of each set (except'the 4. last set) to the first point of the first electrical conductor In the specific example illustrated in Fig. 3, said connecting means takes the form of three wire portions 3; the first wire portion connecting the first point P on electrical conductor 2A to the first point P on electrical conductor 1B, the second portion 3 connecting the first point P on the electrical conductor ZB to ithe first point F on the electrical conductor 1C, and the third wireportion 3 connecting"the'first'point F on the electrical "conductor 2C to the first point F-on the electrical conductorllD.

It should be noted that as illustrated in Fig. 1, each of the electrical 'conducto'rs'is'mounted invertically-Lspaced relationship with respect to a base member, indicated generally at 4, and is connected to a plurality of pins which correspond to the second points S. The ends of each of the electrical conductors may be afiixed to said pins in any suitable manner. It should also be noted that the 'fi'rst'point "F on the first electrical-conductor -1A and 'the fir'st'p'oirit F on the last electrical 'c'onductor lD actual-ly correspond to electrical terminals adaptedfor'c'onnectionto the wheatstone brid'ge' circuit shownin Fig. 3. The e'nds 'of the electrical conductors lA' an'd 2D' rnaybe aiiined tosai'd terminals at'points F in any suitablem'anner.

t sh'ou'ld also benoted that, as shown in :Fig. 1, thecon nectin'g wi're portions ii-are actually integral parts of the electrical-conductors which they connect, and thattthe physical mounting of said ipo'rtions 3 r and the adjacent po'r'tioris of the 'electrical conductors which they :connect, is accomplished-by means i of a. lateral upsta'nding member 5i=provided with -a plurality 1 of holes 6 therein adapted to receive therethrough the left end portions of the appropriate "electrical conductors and adapted to carry along the left e'dgethereof, as'viewed in Fig. l, the connecting portions3.

Also; generally speaking, theopre'sent invention may include electrical contactmeans coop erably arranged for electrical'contact with eachset (or with only one set) of electrical-conductors whereby to electrically connect said first and :second electrical conductors (of each set, .independently). The electrical contactmeansbeing relatively movably mounted with respect to said first and second electrical conductors whereby said electrical contact means-may be relatively moved vin electrical contact with .said first and second electrical conductors (ofveach set) bet-ween-the-first points thereon and'the second points thereon whereby to effectively Vary the electrical resistance-from'the firstpoint on the first electrical conductor tothe-first point onthe second electrical conductor .(or when aplurality of sets is employed, to elfectively vary the electrical-resistance to the first,point.on the first electrical conductor of the first set to .the first point on the second electrical conductor of the last set) as -a function .of the position of the electrical contact-means with respect -to thefirst .and second electrical-conductors (or pluralityof sets thereof) ln-the specific example illustrated, the electrical contact means comprises a plurality of electrical contact members 7, each of which comprises a metallic-spring mounted by suitable rivet means 8 (or the like) with respect to-a transverse member 9, which is provided with two laterally spaced, inwardly directed, tongue means 10 slidably engaged in two opposed outwardly directing corresponding grooves 11 in the base member 4. The

arrangement is such that the entire member? (which is preferably of insulating material) may be slidably moved with respect to the base member 4 in a manner whereby .to similarly slidably move each of the electrical contact members 7 along each set A, B, C, and

D of longitudinal electrical conductors whereby the effective electrical re'sistance'fr'om the "first point P on "the first electrical co'nduct'or 1A through 'a "portion of's'aid conductor, through the first electrical contact member 7, through aportion "of electrical conductor'ZA to "the "first point P 'onlheelectrical conductor '2A, through the trical conductor 1B, through a portion of said conductor, through the second contact member 7, through a portion of the conductor 2D to the first point P thereon, through the second connecting portion 3 to the first point F on electrical conductor 1C, through a portion of said conductor, through the third contact member 7, through a portion of electrical conductor 2C to the first point P thereon, through the third connecting wire 3 to the first point P on the electrical conductor 1D, through a portion of said electrical conductor, through the fourth contact member 7, and through a portion of electrical conductor 2D to the first point F thereon, will be effectively varied in accordance with the positions of the contact members 7 with respect to the sets of longitudinal conductors.

Also, generally speaking, the present invention may include measuring means comprising a first member and a second member relatively movable with respect to each other in correlation with the relative movement of the electrical contact means with respect to the first and second electrical conductors (or plurality thereof).

In the specific example illustrated, the first member of said measuring means actually comprises the member 9 and a longitudinal rod 12 carried thereby, and the second member of said measuring means comprises the base member 4, an upstanding end-plate 13 and a scale 14 carried by the upper surface of the base member 4 immediately adjacent and virtually underlying the longitudinal rod 12. The arrangement is such that a device to be measured, such as the object indicated at 15, may

be removably placed against the upstanding end-plate 13 slidable member 9 may be slidably moved towards the right, as viewed in Fig. 1, until the longitudinal rod 12 abuts the member 15, as shown in Fig. 1. This will cause each of the contact members 7 to assume a position with respect to each set of longitudinal conductors A, B, C, and D correlated with respect to the longitudinal dimension of the object 15, and will, therefore, cause the Overall resistance from the first point F on the first electrical conductor 1A to the first point F on the last electrical conductor 2D to be of a value correlated with respect to the longitudinal dimension of the object 15 between the end of the rod 12 and the upstanding plate 13.

This will cause the balance of the Wheatstone bridge, shown in Fig. 3, to be disturbed and altered with respect to its former position. An operator of the device then visually observes the scale 14 on the upper surface of the base member 4 to determine the measurement of the object 15 to the nearest tenth of an inch and to the nearest fiftieth of an inch, as shown in Fig. 9, and he then adjusts rheostat 16 to the corresponding nearest tenth of an inch reading, and he then adjusts rheostat 17 to the corresponding nearest fiftieth of an inch reading. He then adjusts rheostat 18 until he reaches the highest thousandths of an inch reading which will allow the indicating needle 19 of the meter, indicated generally at 20, to remain at null position. He then adjusts rheostat 21 until he reaches the highest ten-thousandths of an inch position which will allow the needle 19 of the meter 20 to remain at null position. He then adjusts rheostat 21 into the next lowest ten-thousandths of an inch position. He then reads the position of the meter needle 19 to the nearest hundred-thousandth of an inch and approximates the nearest millionth of an inch. Thus the operator may read the longitudinal measurement of the object 15, to a millionth of an inch by merely reading the scale indications of rheostats 16, 17, 18 and 21 and meter 20. For example, the settings of rheostats 16, 17, 18 and 21 and the meter 20, as shown in Fig. 2, correspond with the position of the object 15 with respect to the scale 14, indicated in Figs. 1 and 9, and indicate a measurement of 0.621223 inch. A switch 22 may be employed to etfectively disconnect the meter 20 from the Wheatstone bridge until the rebalancing operation is substantially completed by adjustment of rheostats 16 and 17 (and possibly, the adjustment of rheostat 18 may be approximated). This will tend to protect the meter 20 from excessive current. However, another and better way, is to employ a meter of the type which, under heavy current overload, rotates to the point where torque is lost or greatly reduced, thus preventing any damage to the spring-biasing means associated with the needle 19. Also, the meter wiring can be sufiiciently heavy to prevent coil burn-out under any expected current overload conditions.

Figs. 4, 5, 6 and 7 illustrate a slight modified form of the present invention (Figs. 6 and 7 in fragmentary, diagrammatic, schematic form). Referring to Fig. 6, it will be seen that electrical conductors 1A and 2A, 1B and 2B, 1C and 2C, and 1D and 2D correspond to the electrical conductors shown in Fig. 3 illustrating the first form of the present invention. Also, the first points F on said electrical conductors correspond to the points F shown in Fig. 3 illustrating the first form of the present invention. Also, four electrical contact members 7 correspond to the contact members 7 shown in Fig. 3. Also, the connecting wire portions 3 correspond to those shown in the first form of the present invention at 3. However, in Fig. 4 the second points S of each set of. electrical conductors are connected together by wire portions 23. This does not change the electrical operation of the device, since each of the contact members 7 shorts out the corresponding connecting wire portion 23. The connecting wire portions 23 are merely provided for physical convenience in manufacturing the modified form of the present invention. As best shown in fragmentary form in Fig. 7, the plurality of electrical conductors actually comprise one long continuous wire with the electrical conductors 1A, 2A, 1B, 2B, 1C, 20, 1D and 2D positioned on the inner surface of a cylindrical insulating shell 24 with the connecting wire portions 23 and 3 at opposite ends alternately looped behind projecting end portions 25 of the cylindrical shell 24 whereby to effectively mount the plurality of electrical conductors in the shell 24.

The shell 24 carrying the electrical conductors is mounted in an insulated manner within an outer housing 26, which is closed at the right end, as viewed in Fig. 4, except for a central aperture 27 therein, and which is closed at the left end by a threaded and centrally aper tured cap member 28.

In this modified form of the present invention, the plurality of electrical contact members is indicated at 7 and functionally corresponds to the contact members 7 is shown in the first form of the present invention. The contact members 7 are carried in circumferentially spaced relationship around the periphery of (and an insulating relationship with respect to) a disc-like, slidable member 9, which functionally corresponds to the member 9 shown in Fig. l. The member 9 is provided with a rod 12 which extends to the right, as viewed in Fig. 4, and which is functionally similar to the rod 12 shown in Fig. l, and which is adapted to abut an object 15 which rest against an upstanding end-plate 13, similar to the corresponding elements shown in Fig. 1. However, in the modification shown in Fig. 4, a scale 14 (functionally similar to the scale 14 shown in Figs. 1 and 9) is carried by the right end of the rod 12 and the scale reading for the setting of rheostats 16 and 17 is taken from the junction of the scale 14' with the end wall of the housing 26.

In this modification, the rod 12 is also provided with a leftwardly directed extension (as viewed in Fig. 4) which extends through the apertured cap 28 and which is provided with an actuating handle 29 at the left end thereof. provided with a shoulder 30 abutting a coil compression spring 31, the opposite end of which abutsthe inner surface of the cap 28 whereby to normally bias the right Said leftward extension of the rod 12 is also end of therrodzlZ into icontact with :theobject to :be mcasuredslSf'.

iilh'e operation of :this rmodifiedfdrmlof this .present invention :is- :functionally isi'milarrto the :first.-for1n':hereinbefore-described. Tiiherefore, additional idESGIiPlLiOll is thought.to b'e'unnecessary.

Eig. 8- illustrates a-"slight modification :of'ithe present invention and-comprises the insertion of ta variable irheostat 32 into rthe circuit shown :in :Fig. 3 between rthe Wheatstone bridge :and :the meter 20 for :the purpose of compensating for any overall \change :in :the impedance or'nthe entire Wheatstone bridgeresulting fromsubstantial modification of .the resistance of the ztransducing :leg'and the balancing leg. Ordinarily, such overa'll impedance change isso .slignt so as tob'e unimportant. However, if-idesired, the compensating .rheostat 32 may be employed'andzmay be adjusted ina manner correlated with the reading of any or all of the rheostats 16, .17, 1S and 21 (or the position-of the transducer) so as to fully compensate such overall ibridge impedance change. If desired, the correlation of the rheostat 32, as just mentioned, may be.automatically accomplished by efiectively coupling it with respect to any or all of the other rheostats and/or with respect to the transducer.

Numerous modifications and variations of the present invention will occur -to' those skilled in the art after a careful study hereof. All such properly within the basic spirit and teachings of the present invention are intended to be included and comprehended herein as fully as if specifically described, illustrated and claimed herein.

:For example, variousmeans for producing electricoutput from the apparatus of the present invention, other than the specific multiple-rheostat, Wheatstone bridge and meter arrangement illustrated herein, may be employed. Null. or balancing apparatus may be employed, or positive output signal measuring apparatus may be employed -and either of these may assume a variety of types.

It should also be understood that the electrical conductors which are efiectively connected by the contact meansneed not necessarily be adjacentin fact, they may be oriented in any desired manner. It should also be understood that the two specific structures shown herein, are for illustrative :purposes only. The mechanico-electrical transducer may assume a great variety of-physical structures within the basic teachings hereof. Also, the first and second points, thefirst and second conductors and similar phraseology employed in connection with the plurality of sets may be interchangeable, and such .expressioins are to be interpreted broadlyand not necessarily in the specific manner purposes only.

The exact compositions, configurations, constructions, relative positioningn and cooperative relationships of the various component parts of thepresent invention are not criticaLnnd can bemodified substantially within the-spirit of the present invention.

The embodiments of the presentinvention-specifically described and-illustrated herein are exemplary only, and are not intended to'limit the scope of the jp'resent invention, which is'to be interpreted in the light :ofthe prior art andtheappended claims only, With'due consideration for the doctrine of equivalents.

I claim:

1. A-mechano-electrical transducer, comprising:v a plurality of sets-of electrical conductorsincluding at least a first set anda last set, eachset including affirst electrical conductor having electrical resistance which is a function of the length thereof .from a first point't'hereon to a second point thereon, and a second electrical conductor having electrical resistance which is a"function of the length thereof from aifirst point thereon 'to a second point thereon; means electrically conn'ecting'the first point of the second electrical'conductorof'thefirst set to the'first point or the'firsi electrical eonductor o'f the last set; electrical contact "means cooperably arranged for I electrical Contact described herein for illustrative withrsa'idfirs'tsand: second electrical =conductorsaoffeach act whereby to independently electrically connect. isaidafirst and-second:electrical-conductors of eachset, said electrieal contact "means comprising a :unit relatively Lmovably mountedlforsimultaneous movementaasaufiitwith respect to each'tset ofzele'ctrical conductors whereby :said electrical contact means :may be relatively moved in electrical contact with andtindependently communicating said first and second electrical conductors of. each set between .saidfirst points thereon and said secondpoints thereon "whereby :to effectively vary the electrical resistance from said rst point on said first electrical conductor of said fi'rst' St to "said first point on said second electrical conductor 'o'f said last-set as a function of the position of "the unitary electrical contact means with respect to said plurality of sets of electrical conductors.

2. A 'me'chano-electrical transducencomprising: a plurality of sets of electrical conductors includin'ga first set, a last set and at least one intermediateset each setincluding'a first electrical conductor h'aving electrical resistance which is a function of .the length thereof from afirst point thereon to a 'secondpoi'nt thereon,and a"second electrical conductor having electrical resistaneewhich is a function of the length thereof from a first point thereon to a second point thereon; means electrically connecting the first point of the second electrical c'onductor of the first set to the firstpointof the first electrical conductor-of-an intermediate set and connecting the first point ofthes'ec- 0nd electrical conductor of said intermediate set to the first point of the first electrical conductor of-the "last'set; electrical contact means cooperably 'arranged for'electrical contactw'ith said first and second electrical conductors of each set whereby to independently electrically connect said first and second electrical conductors 'o'fe'ach'setysaid electrical contact means comprising a unitrela'tively movably mounted for-simultaneous movement as a unit with respect to each set of electrical conductors 'wh'ereby'said electrical contact 'm'eansmay be relatively'movedin'electrical contact with and independentlycommunicating said first and second electrical conductors of each set between said first points thereon and said second points thereon whereby to efiec'tively vary the electrical resistance 'from said 'first point on said first electrical conductor of said first set to said first point on said second electrical .conductor of said last set as a function ofthe position of the unitary electrical contact means with respect to saidplurality of sets of electrical conductors.

3. A mechano-electrical transducer, comprising: a plurality of sets-of electrical conductors including a first set, a last set and a plurality of intermediate sets, each set including .a first electrical conductorhaving electrical resistance which is a function of the length thereofffrom a first-point thereon to a second point thereon, and a second electrical conductorhavingelectrical resistance which'is a function of. the length.thereoffrom'a"firstpoint thereon to a second point thereon; means electrically connecting'the first :point-of the second electrical conductor or eachset except the .last set to the .first point of the'first electrical conductor-of-a difierent .set except the first set;electrical contact means including a .plurality of electrically independent but .-mechanically connected electrical contact members each cooperably arranged for independent electricalcontact-withsaidfirst and secondelectrical conductors of each set whereby.toindependently electrically connectisaid-fir-stand second electrical conductors .or each set, .said electrical contact means comprisinga unit rela tively movably mountedtonsimultaneous movement as a unit with respecttoeachset of'electrical conductors whereby said electrical-contactmeans may be relatively moved in 'ele'ctrical' contact with andindependently communicating said first :and second electrical conductors :of :eachset between said ".first points thereon and:Sald. SBCOIld points thereon whereby .to effectively vary .the electrical. resistance from said firstpointon saidlfirstelectrical-conductor of said first set to said first point on said second electrical conductor of said last set as a function of the position of the unitary electrical contact means with respect to said plurality of sets of electrical conductors.

4. A mechano-electrical transducer, comprising: a plurality of sets of electrical conductors including at least a first set and a last set, each set including a first electrical conductor having electrical resistance which is a function of the length thereof from a first point thereon to a second point thereon, and a second electrical conductor having electrical resistance which is a function of the length thereof from a first point thereon to a second point thereon; means electrically connecting the first point of the second electrical conductor of the first set to the first point of the first electrical conductor of the last set; electrical contact means cooperably arranged for electrical contact with said first and second electrical conductors of each set whereby to independently electrically connect said first and second electrical conductors of each set, said electrical contact means comprising a unit relatively movably mounted for simultaneous movement as a unit with respect to each set of electrical conductors whereby said electrical contact means may be relatively moved in electrical contact with and independently communicating said first and second electrical conductors of each set between said first points thereon and said second points thereon whereby to effectively vary the electrical resistance from said first point on said first electrical conductor of said first set to said first point on said second electrical conductor of said last set as a function of the position of the unitary electrical contact means with respect to said plurality of sets of electrical conductors; measuring means including a first member and a second member relatively movable with respect to each other in correlation With the simultaneous relative movement of the unitary electrical contact means with respect to each set of electrical conductors.

5. A mechano-electrical transducer, comprising: a plurality of sets of electrical conductors including a first set, a last set and at least one intermediate set, each set including a first electrical conductor having electrical resistance which is a function of the length thereof from a first point thereon to a second point theron, and a second electrical conductor having electrical resistance which is a function of the length thereof from a first point thereon to a second point thereon; means electrically connecting the first point of the second electrical conductor of the first set to the first point of the first electrical conductor of an intermediate set and connecting the first point of the second electrical conductor of said intermediate set to the first point of the first electrical conductor of the last set; electrical contact means cooperably arranged for electrical contact with said first and second electrical conductors of each set whereby to independently electrically connect said first and second electrical conductors of each set, said electrical contact means comprising a unit relatively movably mounted for simultaneous movement as a unit with respect to each set of electrical conductors whereby said electrical contact means may be relatively moved in electrical contact with and independently communieating said first and second electrical conductors of each set between said first points thereon and second points thereon whereby to etfectively vary the electrical resistance from said first point on said first electrical conductor of said first set to said first point on said second electrical conductor of said last set as a function of the position of the unitary electrical contact means with respect to said pluraltiy of sets of electrical conductors; measuring means including a first member and a second member relatively movable with respect to each other in correlation with the simultaneous relative move' ment of the unitary electrical contact means with respect to each set of electrical conductors.

6. A mechano-electrical transducer, comprising: a

plurality of sets of electrical conductors including a first set, a last set and a plurality of intermediate sets, each set including a first electrical conductor having electrical resistance which is a function of the length .thereof from a first point thereon to a second point thereon, and a second electrical conductor having electri cal resistance which is a function of the length thereof from a first point thereon to a second point thereon; means electrically connecting the first point of the second electrical conductor of each set except the last set to the first point of the first electrical conductor of a dilferent set except the first set; electrical contact means including a plurality of'electrically independent but mechanically connected electrical contact members each cooperably arranged for independent electrical contact with said first and second electrical conductors of each set whereby to independently electrically connect said first and second electrical conductors of each set, said electrical contact means comprising a unit relatively movably mounted for simultaneous movement as a unit with respect to each set of electrical conductors whereby said electrical contact means may be relatively moved in electrical contact with and independently communicating said first and second electrical conductors of each set between said first points thereon and said second points thereon whereby to effectively vary the electrical resistance from said first point on said first electrical conductor of said first set to said first point on said second electrical con ductor of said last set as a function of the position of the unitary electrical contact means with respect to said plurality of sets of electrical conductors; measuring means including a first member and a second member relatively movable with respect to each other in correlation with the simultaneous relative movement of the unitary electrical contact means with respect to each set of electrical conductors.

7. A mechano-electrical transducer, comprising: a plurality of sets of electrical conductors including at least a first set and a last set, each set including a first long thin electrical conductor having electrical resistance which is a function of the length thereof from a first point thereon to a second point thereon, and a second long thin electrical conductor having electrical resistance which is a function of the length thereof from a first point thereon to a second point thereon, said first and second long thin electrical conductors and said first and second points thereon being in laterally adjacent, similarly oriented relationship; means electrically connecting the first point of the second electrical conductor of the first set to the first point of the first electrical conductor of the last set; electrical contact means cooperably arranged for relative slidable electrical contact with said first and second electrical conductors of each set whereby to independently electrically connect said first and second electrical conductors of each set, said electrical contact means comprising a unit relatively slidably mounted for simultaneous movement as a unit with respect to each set of electrical conductors whereby said electrical contact means may be relatively moved in electrical contact with and independently communicating said first and second electrical conductors of each set between said first points thereon and said second points thereon whereby to elfectively vary the electrical resistance from said first point on said first electrical conductor of said first set to said first point on said second electrical conductor of said last set as a function of the position of the unitary electrical contact means with respect to said plurality of sets of electrical conductors.

8. A mechano-electrical transducer, comprising: a plurality of sets of electrical conductors including a first set, a last set and at least one intermediate set, each set including a first long thin electrical conductor having electrical resistance which is a function of the length thereof from a first point thereon to a second point thereon, and a second long thin electrical conductor having electrical a first pointthereon to asecond pointthereon, said first and second long thin electrical conductors; and said. first and second points thereon being, in laterally adjacent,

similarly oriented relationship; means electrically conmeeting; the first point ofv the second electrical conductor, of the first set to the first point of the first electrical. conductor of an intermediate set and connectingthe,firstpoint of the second electricalconductor of, said intermediate set to the first point of the first electrical conductor of; the last set; electrical contact means cooperabiy arranged for relative slidable electrical contact with said first and second electrical conductors of each set whereby to independently electrically connect said firstvand second electrical conductors of each set, said electrical contact means com: prising a unit relatively slidably mounted for simultaneous slidable movement as avunit with respect to each set of electrical conductors whereby said electrical contact means may be relatively slidably moved in electrical contact with and independently communicating said first and second electrical conductors of each set between said first points thereon and said second points thereon whereby to effectively vary the electrical resistance from said first point on said first electrical conductor of said first set to said first point on said second'electrical conductor of said last set as a function of the position of the unitary electrical contact means with respect to said plurality .of

sets of electrical conductors.

9. A mechano-electrical transducer, comprising: a plurality of sets of electrical conductors including a first set, a last set and a plurality of intermediate sets, each set in: cluding a first long thin electrical conductor having electrical resistance which is afunctionof the length thereof from a first point thereon to a second point thereon, and

a second long thin electrical conductor having electrical resistance which is a function of the'length thereof from a first point thereon to a. second point thereon, said" first and second long thin electrical conductors. and said first and second" points thereon being-in laterally adjacent, similarly oriented relationship; means electrically connecting the first point of the second electrical conductor of each set except the last set to the first point of the first electrical conductor of a different set except thefirst set; electrical contact means including'a plurality of electrically independent but mechanically connected electrical contact members each cooperably slidably arranged for electrically independent but physically' simultaneous slidable electrical contact'with saidifirst'and second electrical conductors of each set whereby to independently electrically connect said first and second el'ectricalconductors of each set, said electrical contact means comprising a unit ,relatively slidably mounted for simultaneous slidable movement as a unit with respect-to each setor" electrical conductors whereby said electrical contact means may be relatively moved in electrical contact with and'independently communicating said first andsecond electrical conductors of each set'between said-'first-points thereon and said second points thereon whereby-to effectively vary the electrical resistance fromsaid'first point on saidfirst el'ectricaltconductor of said'first set to sai'd first point on said second electrical conductor of said last-set as a func tion of the position of the unitaryelectrical contact means with respect tosaid plurality of sets of electrical condoctors.

A mechano-electrical transducer, comprising: a plurality of setsof electrical conductors including at least a first set and a'last set, each set. including a first long thin electrical conductor having electrical resistance which is a function of the length thereof from a first pointthereonto .a second. poin thereon, and a second" long thin electrical conductor having electrical resistance which is a function of'the length thereoffroni a first point thereon to a second point thereonsaid first and second longth in electrical conductors and said first and second points thereon being in laterally adjacent, similarly oriented relationship; meanselectrically-connecting the first point 0E5 the secondelectrical conductor of the first set to the first point. of the first electrical conductor of the last set; electrical contact means cooperably arranged for relative slidable electrical contact with said first and second electrical conductors of each set whereby to, independently electrically connect said first and second electrical condoctors of enchset, said electrical contact means comprising a unit, relatively slidably mounted for simultaneous movement as a unit with respect to each set of electrical conductors whereby said electrical contact means may be relatively moved in electrical contact with, and independently communicating said first andsccond electrical conductors of each set between said first points thereon andsaidsecond points thereon whereby to effectively vary the electrical resistance from said first point on said first electrical conductor of said first, set to said, first point on said second electrical conductor of said last set as a function of the position of the unitary electrical contact means with respect to said plurality of sets of electrical conductors; measuring means including, a first member fixed with respect to saidsets of electrical conductors, and a second member ,fiXcdwith respect to said electrical con-- tact means whereby said first member and said second member will ,be relatively movable With respect to each other inr-cerrclation with the simultaneous relative move: ment of the unitary electrical contact means with respect toceachset of electrical conductors.

1-1. A ,mechanmelcctrical transducer, comprising: a plurality. .of vsets of electrical conductors including a first set, a last: set and at least one intermediate set, each set including a first, long thin electrical conductor having electricalgresistance which isa function of the length thereof from a first point-thereon to a second point thereon, and a second long thin electrical conductor having electrical resistance which, is a function of the length thereof fromatfirst pointrthereon-to a second point thereon, said first and second. long thin electrical conductors and said first ancl' second points thereon being inlaterally adjacent, similarly oriented relationship; means electrically connectingthefirst point of the second electrical conductor of the first. set, to the :first point of the first electrical conductor of an intermediate set and connecting the first pointof.. the ,secondelectrical conductor of said intermediat et to-thefirstpoint of the first electrical conductor .of ;the.:last setg; electrical contact means cooperably arranged; for relative slidable electricalcontact with said first and second electrical conductors of each setwherebyto independently electrically connect said first and second electrical conductors of each set, said electrical contact means comprising a unit relatively slidably mounted for simultaneous-slidablemovement as a unit withrcspectto each set ofclectrical conductors whereby said electrical contact-means may be relatively slidably moved in, electrical contact with and independently communicating saidifirstand second electrical conductors of each setbetween said first points thereon and said second points thereon whereby to effectively vary the electrical resistance from saidfirst point on said first electrical conductor of said first sct to said fi-rstpoint on said second electrical conductor of said last set as afunction of the position. of the unitary electrical contact means with respect to said plural-ityof sets, of electricalconductors; measuring means inclnding arfirst, member fixed with respect to saidsets of ele, calrconductors, and a second member fixed with respect to said electrical contact means whereby said.

firstmember and said secondmemberwill be relatively movablewithrespectto; each other in correlation With the simultaneous relat-i-vernovementot the unitary electrical contact, -m eans ,with respect to each set of electrical conductors.

12. A rnechangrelectrical transducer, comprising: a plurality of sets ot ;e ctrical conductors including a first set, 3,1,5Sl, set; and apluralityot interme iate sets, eachset including a first long, thin electrical conductor having electrical. resistance which is a function of the lcngth thereof from a first point thereon to a second point thereon, and a second long thin electrical conductor having electrical resistance Which is a function of the length thereof from a first point thereon to a second point thereon, said first and second long thin electrical conductors and said first and second points thereon being in laterally adjacent, similarly oriented relationship; means electrically connecting the first point of the second electrical conductor of each set except the last set to the first point of the first electrical conductor of a different set except the first set; electrical contact means including a plurality of electrically independent but mechanically connected electrical contact members each cooperably slidably arranged for electrically independent but physically simultaneous slidable electrical contact with said first and second electrical conductors of each set whereby to independently electrically connect said first and second electrical conductors of each set, said electrical contact means comprising a unit relatively slidably mounted for simultaneous slidable movement as a unit with respect to each set of electrical conductors whereby said electrical contact means may be relatively moved in electrical contact with and independently communicating said first and second elec- 'trical conductors of each set between said first points thereon and said second points thereon whereby to effectively vary the electrical resistance from said first point on said first electrical conductor of said first set to said first point on said second electrical conductor of said last set as a function of the position of the unitary electrical contact means with respect to said plurality of sets of electrical conductors; measuring means including, a first member fixed with respect to said sets of electrical conductors, and a second member fixed with respect to said electrical contact means whereby said first member and said second member will be relatively movable with respect to each other in correlation with the simultaneous relative movement of the unitary electrical contact means with respect to each set of electrical conductors.

References Cited in the file of this patent UNITED STATES PATENTS 2,144,216 Broome Ian. 17, 1939 

